High intensity driving lamps particularly for road vehicles

ABSTRACT

A sealed beam lamp includes a reflector, having a lens secured thereto and defining therewith a sealed enclosure. A quartz iodine or equivalent high intensity bulb is located within said enclosure, and is carried by the reflector, and a light shield for preventing light from the bulb issuing from the lamp, without first being reflected from the reflector, is associated with the bulb.

United States Patent IIIGII INTENSITY DRIVING LAMPS PARTICULARLY FORROAD VEHICLES 8 Claims, 5 Drawing Figs.

u.s. c1. 313/113, 240/41.35,240/41.4,313/117 FieldofSearch 313/113- [56]References Cited UNITED STATES PATENTS 1,439,313 12/1922 Landis240/46.55 1,772,175 8/1930 Arbuckle 240/4125 1,927,285 9/1933 Hurrell etal 240/4655 3,107,866 10/1963 Nowak 240/4125 3,445,646 5/1969 Brooks etal 240/41.35X

Primary Examiner-James W. Lawrence Assistant Examiner-David OReillyAttorney-Holman & Stern 1113 j J! I 147 in FIG. 1,

all drawn to the same scale.

HIGH INTENSITY DRIVING LAMPS PARTICULARLY FOR ROAD VEHICLES Thisinvention relates to sealed beam lamps for road vehicles.

Generally, the present invention relatesto a high intensity driving lampcomprising a reflector and a lens secured to the reflector around itsperiphery for defining a sealed enclosure therebetween, a quartz halogenbulb fixedly secured to the reflector within the enclosure, connectingleads for the bulb extending within the enclosure, said enclosure havingan at mosphere which is nonoxidizing with respect to said connectingleads.

One example of the invention is illustrated in the accompanying drawingswherein:

v.FIG. l is a sectional view of a sealed beam lamp for a road vehicle,

FIG. 2 is a sectional view on the line 2-2 in FIG. 1,

FIG. 3 is a perspective view of the quartz iodine bulb shown FIG. 4 is aperspective view of a light shield shown in FIG. 1 and FIG. 5 is aperspective view of the ceramic bulb support shown in FIG. 1, it beingappreciated that FIGS. 1 to 5 are not Referring to the drawings, thelamp ncludesan outer casing 11 adapted at 12 to be secured to a roadvehicle. Secured within the casing 11, by means of a clamping ring 13,is a sealed beam lamp unit 14, including a paraboloidal reflector 15 andan integral lens 16, the sealed enclosure defined by the lens 16 and thereflector 15 being filled with an inert atmosphere. The reflector 15 ismoulded in glass and secured to the outer surface thereof is a pair ofconductive blade terminals 17, 18. Extending through sealed pinches 19,21 in the reflector 15, adjacent the terminals 17, 18 is a pair of stiffconductive leads 22, 23 electrically connected respectively to theterminals 17, 18. The production of the pinches 19, 21 results in localdistortion of the inner surface of the reflector adjacent the pinchesand when the inner surface of the reflector is aluminized to render ithighly reflective the area of the inner surface of the reflector 15adjacent the pinches 19, 21 is masked so that the distorted areas of thereflector are not aluminized. Thus the amount of light which will. bescattered by the distorted areas of the reflector 15 is minimized.

The leads 22, 23 extend forwardly from the reflector, for a shortdistance, parallel with the axis of the reflector and are then, bentthrough 90 to extend towards one another for a further short distance.

Extending parallel with the axis of the reflector are a further pair ofconductive leads 24, 25 which are welded at one end to the free ends ofthe leads 22, 23 respectively. The leads 24, 25

extend through corresponding parallel bores 27 in a ceramic bulb supportmember 26. The member 26 comprises a rectangular block 28 of ceramicmaterial having a pair of parallel fingers 29 integral therewith andextending from one end thereof. The end of the block 28 remote from thefingers 29 is formed with a transverse groove 31 in which the bentportions of the leads 22, 23 lie. The bores 27 extend from the base ofthe groove 31 and terminate between the fingers 29.

Engaged with the member 26 is a quartz iodine bulb 32. The bulb 32comprises a generally cylindrical quartz envelope 33 housing a tungstenfilament 34. Thebase of the bulb 32 is formed by a pinch 35 and enclosedin thickened edges 36 of the pinch 35 are a pair of conductive ribbons37, 38 which at one end are interconnected by the filament 34 and whichat their other ends are connected to the leads 24, 25 respectively sothat an electrical circuit between the terminals 17, I8 is completedthrough the filament 34. Between the edges 36 of the base of the bulb isan integral web 39 and the bulb 32 is engaged with the member 26 byinserting the web 39 between the fingers 29 of the member 26 until thefree end of the web 39 engages the block 28 of the member 26, the member26 serving to minimize flexure of the leads 22, 23, 24, 25 in use andthereby to minimize movement of the bulb relative to the reflector.

Trapped between the base of the bulb'32 and the member 26 is a rearlight shield 41 which includes a pair of side portions 42 which extendparallel with the axis of the reflector l5 and which masks the edges 36of the pinch 35 and the deformed parts of the envelope 33 adjacent theedges 36, and a top portion 43. The portion 43 includes apart 430 whichextends at right angles to the axis of the reflector l5 and integralwith the part 43a is a further part 43b which extends parallel with theaxis of the reflector. The portion 43 masks the deformed part of theenvelope 33 adjacent the web 39 which is uppermost in use.

Extending parallel with the leads 22, 23 from a third pinch 44 in thereflector 15 is a rigid rod 45 which at its end remote from thereflector 15 carries a front light shield 46. The shield 46 is in theform of a cup-shaped member which encloses the forward end of theenvelope 33. The shield 46 includes a resilient metal strip 47 whichengages the envelope 33 at a pair of spaced points and the shield 46itself engages the envelope at a third point which is the lowermostpoint of the envelope 33 in use, so that the envelope is held againstmovements in directions transverse to the axis of the reflector 15 bythe shield 46 and the rod 45, in addition to member 26. The manufactureof the envelope 33 involves the formation of a pinch 33a at the end ofthe envelope 33 remote from the reflector 15, the pinch 33a beingenclosed within the shield 46. The edge of the shield 46 lies on thesurface of a cone having its apex at the center of the filament 34 andits base at the front edge of the reflector so that ny any light fromthe filament 34 which is travelling in a direction such that it wouldpass directly through the lens 16, without first being reflected fromthe reflector 15 is blocked by the shield 46.

In use when the lamp is assembled the leads 24, 25 are welded to theribbons 37 38 of the bulb 32 and the rear shield 41 is engaged with thebase of the bulb 32, a pair of tags 42a integral with the side portions42 of the shield 41 being deformed to grip the web 39 of the bulb 32.The bulb 32 and shield 41 are then engaged between the fingers 29 of themember 26 with the leads 24, 25 extending through the bores 27 of themember 26 into the groove 31. The ends of the leads 24, 25 are thenwelded to the ends of the leads 22, 23 respectively so that the bentportion leads 22, 23 he in the groove 31. The shield 46 is then engagedwith the erivelope33 of the bulb 32 and is moved to its correctposition, a tag 47a integral with the strip 47 of the shield 41 beingwelded to the rod 45 to support the bulb 32 firmly in position relativeto the reflector 15.

It is important when using a high intensity lamp that light from thelamp is directed down onto the road and that a minimal amount of lightis scattered upwardly from the lamp. It will be appreciated, that thepinch 33a, if it were not masked by the shield 41, would scatter lightfrom the filament 34 in all directions. Moreover the deformed areas ofthe envelope 33 around the pinch 35, and the pinch 35 itself, refractthe light from the filament and so constitute light sources themselves.The additional light sources constituted by the pinch 35 and itssurrounding part of the envelope 35 are behind the focal point of thereflector l5 and so would produce a divergent beam issuing from thelamp. However the side portions 42 and the top portion 43 of the rearshield 4] block all of the light which would produce such a divergentbeam with exception of that part of the light issuing from the lowermostpart of the envelope 33 which would result in a divergent beam directeddownwardly onto the road. Furthermore, the portion 43 of the shield 41is also positioned to block any light which would be reflected from thedeformed area of the reflector 15 around the pinch 44, since the areaaround the pinch 44 unlike the areas around the similar pinches 19, 21is aluminized when the reflector is manufactured and so is highlyreflective. The area around the pinch 44 is not masked with the areasaround the pinches 19, 21 during the aluminizing process, since it hasbeen found more convenient to utilize the shield 41 to preventreflection from the area around the'pinch 44.

In conventional lamps employing quartz iodine or equivalent highintensity bulbs, unless great care is taken in design to avoidexcessively high temperatures near the pinch 35 there is a possibilityof early failure of the bulb because of gradual-oxidation of the ribbons37, 38. This oxidation causes the ribbons 37, 38 to swell andtheswelling eventually cracks the pinch 35, allowing air to enter thebulb, whereupon the bulb burns out. Since the bulb 32 of the presentconstruction is housed in an enclosure containing an inert atmosphere,the ribbons 38, 39 cannot oxidize, so this hazard does not arise.

It will be appreciated that the light shield 46, and in particular thelight shield 41, are so constructed that they do not scatter the lightwhich they are intended to block in directions which would havedeleterious effects on the accurate high intensity beam issuing from thelamps.

lclaim:

l. A high intensity driving lamp comprising a reflector and a lenssecured to the reflector around its periphery for defining a sealedenclosure therebetweema quartz halogen bulb fixedly secured to thereflector within the enclosure, connecting leads for the bulb extendingwithin the enclosure, said enclosure having an atmosphere which isnonoxidizing with respect to said connecting leads, and a light shieldassociated with the bulb for preventing light which has not first beenreflected from the reflector issuing from the lamp.

2. The high intensity lamp as claimed in claim 1 in which said lightshield is secured to the reflector and is engaged with the bulb andserves to support the bulb.-

3. The high intensity lamp as claimed in claim 1 in which said shieldincludes a cuplike portion enclosing the forward end of the bulb, withthe free edge of said cuplike portion and the periphery of the reflectorlying upon the surface of an imaginary cone, the apex of the imaginarycone being at the center of the bulb filament whereby the light shieldprevents light from the bulb which has not first been reflected from thereflector issuing from the lamp.

4. The high intensity lamp as claimed in claim 1 in which the areas ofthe reflector through which said connecting leadsextend into theenclosure are substantially non'reflective. g

5. The high intensity lamp as claimed inclaim 1 further including asecond light shield positioned with respect to the bulb to prevent thoselight rays which have been reflected by the bulb at the base thereof andwhich would be reflected by the reflector to issue from the lampupwardly relative to the axis of the reflector, from striking thereflector.

6. The high intensity lamp as claimed in claim 5 in which the portionsof said second light shield which block light from'the portion of thebulb at the base thereof are so positioned.that the refracted rays arenot scattered by the shield in directions having a deleterious effect onthe beam produced by the lamp.

7. The high intensity lamp as claimed in claim I in which saidconnecting leads are engaged with a rigid heat resistant member servingto minimize flexure of the leads.

8. The high intensity lamp as claimed in claim 7 further including asecond light shield positioned with respect to the bulb to prevent thoselight rays which have been refracted by the portion of the bulb at thebase of the bulb and which would be reflected by the reflector to issuefrom the lamp upwardly relative to the reflector in use, fromstriking-the reflector and said second shield being engaged with saidheatresistant member.

1. A high intensity driving lamp comprising a reflector and a lenssecured to the reflector around its periphery for defining a sealedenclosure therebetween, a quartz halogen bulb fixedly secured to thereflector within the enclosure, connecting leads for the bulb extendingwithin the enclosure, said enclosure having an atmosphere which isnonoxidizing with respect to said connecting leads, and a light shieldassociated with the bulb for preventing light which has not first beenreflected from the reflector issuing from the lamp.
 2. The highintensity lamp as claimed in claim 1 in which said light shield issecured to the reflector and is engaged with the bulb and serves tosupport the bulb.
 3. The high intensity lamp as claimed in claim 1 inwhich said shield includes a cuplike portion enclosing the forward endof the bulb, with the free edge of said cuplike portion and theperiphery of the reflector lying upon the surface of an imaginary cone,the apex of the imaginary cone being at the center of the bulb filamentwhereby the light shield prevents light from the bulb which has notfirst been reflected from the reflector issuing from the lamp.
 4. Thehigh intensity lamp as claimed in claim 1 in which the areas of thereflector through which said connecting leads extend into the enclosureare substantially nonreflective.
 5. The high intensity lamp as claimedin claim 1 further including a second light shield positioned withrespect to the bulb to prevent those light rays which have beenreflected by the bulb at the base thereof and which would be reflectedby the reflector to issue from the lamp upwardly relative to the axis ofthe rEflector, from striking the reflector.
 6. The high intensity lampas claimed in claim 5 in which the portions of said second light shieldwhich block light from the portion of the bulb at the base thereof areso positioned that the refracted rays are not scattered by the shield indirections having a deleterious effect on the beam produced by the lamp.7. The high intensity lamp as claimed in claim 1 in which saidconnecting leads are engaged with a rigid heat resistant member servingto minimize flexure of the leads.
 8. The high intensity lamp as claimedin claim 7 further including a second light shield positioned withrespect to the bulb to prevent those light rays which have beenrefracted by the portion of the bulb at the base of the bulb and whichwould be reflected by the reflector to issue from the lamp upwardlyrelative to the reflector in use, from striking the reflector and saidsecond shield being engaged with said heat resistant member.